Answer
Air quality in Chiang Mai can be quite variable, especially during the burning season, which typically occurs from February to April.
• During this time, agricultural burning in the surrounding areas can lead to increased levels of PM2.5 pollutants, making the air quality poorer and visibility lower.
• In contrast, the cooler months from November to February generally see clearer skies and better air quality, making it a popular time for outdoor activities and sightseeing.
Practical Chiang Mai planning note: For weather and air quality, check a current forecast and a live air-quality source shortly before the activity. Northern Thailand can experience strong seasonal variation, and conditions differ between the city, foothills and higher mountains.